1. Field of the Invention
The invention is classified as an "Advanced reciprocating piston driven engine." This field of classification refers to any engine system in which movement of the piston is not a simple function of the harmonic motion induced by rotation of the crankpin.
2. Description of Prior Art
In the conventional piston driven engine system the reciprocating mechanism is described in classical terms as a four-bar linkage and sliding member. The invention presented consists of two four-bar linkages operating in conjunction with a sliding member.
Pressure forces developed at the piston face are transmitted to the crankpin through a central connecting rod which transfer the load to two lateral connecting rods which in turn transmit the load to the end portions of the crankpin at the point of attachment to the crank arms. The central connecting rod is attached to the center portion of the crankpin, the axial alignment of which is displaced from the longitudinal axis of the end sections of the crankpin which carry the two lateral connecting rods. This is therefore seen to be a compound crank in which the rate of change in angularity of the two lateral connecting rods, during shaft rotation, is different from that of the central connecting rod when measured relative to the axial center of the cylinder bore.
The advantage of the invention over that of the conventional reciprocating engine is the ability to control piston speed in a manner which is more consistent with the particular engine application. When rotation of the crankshaft is in the clockwise direction, the piston speed during the initial downward expansion stroke is decreased allowing more effective crank angles to develope at the essentially higher cylinder pressures. The higher cylinder pressures produced at the more effective crank angles result in a correspondingly more powerful engine. The slower piston speed, in conjunction with the shorter piston stroke, decrease the amount of cylinder wear resulting in a correspondingly longer operational life of the engine system.
There are also certain advantages to be gained in operating the system in a counter clockwise rotation of the crankshaft. These are seen to be in somewhat the better mechanical advantage at the initial expansion.